[Freeflow]

I was helping a chap do his DM map at Guildy a few years ago, and after a couple of twinset dives we dropped in for 10 min to check out some stuff on the 8m platforms. I had 80 bar in my twin 12's, plenty for a pootle like that.

Right up to the point where there was a very loud bang, followed by the sound of a lot of gas escaping. The done thing on twins is to shut them down when something goes wrong. Ths time though it's not the classic freeflowing reg, so which side do I shut down?

My buddy is 5-6m away and taking notes, so he hasn't seen the bubbles, but when I hit him full on he wakes up and shuts off my left tank.

On the surface we see that the BC inflator hose has split, dumping a lot of gas quickly. We were in for about 5-8 min when this happened,and the shut down probably took all of 15 seconds [including the swim over] and I had 12 bar left.

Now, you may think that I was diving on a knackered hose. It was 18 months old and had split on the second thread inside the ferrule, where you can't see the damage without taking the hose end apart. I am still diving an 8 year old hose of the same make [AP Valves] with no problems-yet.

The most important thing in diving is to not get too fixated on the way you are taught to problem solve. 'Officially' I should have done the shut down myself. I may have felt the bubbles from the left post when I reached back, but I may not have done, so I would have been doing the full shut down. My buddy could instantly see the problem and sort me out, and probably saved me some gas.